A researcher prepared a pedigree (family tree) to trace a genetic disorder in a family - HSC - SSCE Biology - Question 6 - 2006 - Paper 1

To determine how the gene that causes the condition can be described, we need to look at the characteristics of the inheritance patterns observed in the pedigree. The fact that the disorder appears in both males and females suggests that it is not linked strictly to sex. Furthermore, if it were recessive, it might skip generations, whereas if it is dominant, it would typically appear in every generation. Since the question does not indicate skipping generations or observable patterns suggestive of co-dominance or sex-linkage, the most likely answer is that the gene is classified as dominant. Therefore, the correct choice is (B) Dominant.